The present invention relates to a device and a method for monitoring process exhaust gas a semiconductor manufacturing device equipped with the monitoring device, and a system and a method for controlling the semiconductor manufacturing device, and, more particularly, to a device and a method for monitoring process exhaust gas by analyzing the gas components of various types exhausted during a semiconductor manufacturing process, a semiconductor manufacturing device equipped with such a monitoring device, and a system and a method for controlling such a semiconductor manufacturing device.
Generally, various types of process gases are used in the manufacturing process of a semiconductor circuit. In a semiconductor manufacturing device for manufacturing semiconductor devices using process gases, the process conditions are monitored so as to process semiconductor wafers stably and accurately. The process conditions to be monitored include the process gas flow rates, the pressure and temperature in the process chamber, the RF power, the RF reflected wave, the voltage of electrostatic chuck, and the coolant gas pressure.
FIG. 1 is a schematic view of the entire structure of a semiconductor manufacturing device including a conventional monitoring device. The semiconductor manufacturing device shown in FIG. 1 includes a RF plasma processing-device 2, a controller 4 for controlling each operation of the semiconductor manufacturing device, a power source unit 6, a process gas supply device 8, and a gas flow meter 10. These devices are arranged in a housing 12, and function in cooperation with one another as one semiconductor manufacturing device.
The RF plasma processing device 2 carries out a predetermined process using plasma on a process object to be processed (e.g., a semiconductor wafer). The process object to be processed is subjected to the plasma processing in a process chamber 2a. Process gas is supplied as a plasma source from the process gas supply device 8 into the process chamber 2a. Other various gases for controlling the process environment in the process chamber 2a are also supplied to the process chamber 2a. The flow rates of the process gas and the other various gases supplied into the process chamber 2a are measured and monitored by the gas flow meter 10.
As a result of the processing of the process object, exhaust gas is generated in the process chamber 2a. Below the process chamber 2a, a turbo molecular pump (TMP) 2b is provided to suck the exhaust gas from the process chamber 2a and then discharge the exhaust gas to an exhauster 14. The exhaust gas is then exhausted from a dry pump 16 via the exhauster 14 to a device such as a cleaning device (not shown).
In the semiconductor manufacturing device having the above structure, various sensors are provided in the RF plasma processing device 2, so as to monitor the process conditions. More specifically, the RF power and its reflected wave supplied to the RF plasma processing device 2 are monitored. The pressure and the temperature in the process chamber 2a of the RF plasma processing device 2 are also monitored. Furthermore, an electrostatic chuck for securing the process object to be processed (a semiconductor wafer) is provided in the process chamber 2a, and the voltage supplied to the electrostatic chuck is monitored. Also, the temperature of coolant gas that is supplied to the electrostatic chuck and controls the temperature of the electrostatic chuck is monitored. In the turbo molecular pump 2b for exhausting gas from the process chamber 2a, the pressure of the exhaust gas is monitored.
While monitoring those conditions, the semiconductor manufacturing device controls each of the process conditions in the semiconductor manufacturing process, so that a desired process is carried out for the process object that is being processed.
In the above conventional monitoring device, each of the process conditions is individually detected and controlled. More specifically, a reference value and a tolerable range are set for each of the process conditions, and a control operation is performed by adjusting the process condition to the reference value or maintaining the process condition within the tolerable range. Here, each of the process conditions is individually controlled, and the correlations between the process conditions are not taken into consideration and therefore are not monitored.
An actual process carried out for a process object is affected by the process conditions closely interrelated with one another. When a large number of process objects are continuously processed, the process conditions affects one another, and the result of the actual process on the process objects might change beyond the tolerable range, even if the process conditions change with time only within the tolerable range. In such a case, even though the actual process conditions as a whole change beyond the normal tolerable range, the process for the process objects are determined to be properly carried out, just because each of the process conditions is within each corresponding tolerable range.
In a semiconductor manufacturing device using the above conventional monitoring device and method, each process object after a process is subjected to test analysis to determine whether the process object is a proper product, i.e., whether the process has been properly performed. In other words, in a semiconductor manufacturing device using the conventional monitoring device, whether the process conditions are in a normal state cannot be checked before an actual process is completed.
A test on a processed object requires a certain period of time. For instance, when a large number of process objects are continuously processed, processed ones are stored until the process for the last process one is completed, and all the processed objects are then subjected to test analysis at once.
In this manner, even though the process conditions as a whole move outside the normal range, the process is continued, as long as each of the process conditions is within each corresponding tolerable range. As a result, a large number of process objects are processed under the abnormal process conditions.
The general object of the present inventions is to provide a device and method for monitoring process exhaust gas a semiconductor manufacturing device, and a system and method for controlling semiconductor manufacturing devices, in which the above described problems with the prior art are eliminated.
A more specific object of the present invention is to provide a process exhaust gas monitoring device and method, which compare the amount of exhaust gas from a process chamber under optimum process conditions with the amount of exhaust gas generated during an actual process, and detect a change in the gas amount to monitor the entire balance among the process conditions, thereby performing a process monitoring operation that is effective with changes over time. A semiconductor manufacturing device equipped with the above monitoring device is also provided by the present invention.
Another specific object of the present invention is to provide a system and method for controlling semiconductor manufacturing device, which can control the semiconductor manufacturing devices with a high precision by accumulating analysis data obtained from an exhaust gas analysis made in the semiconductor manufacturing devices. With this system and method, the semiconductor manufacturing devices can be efficiently operated.
To achieve the above objects, one aspect of the present invention provides a process exhaust gas monitoring device that monitors the amount of each component of process exhaust gas containing a plurality of gas components resulted from a process carried out for a process object under predetermined process conditions. This monitoring device includes:
gas sampling means for sampling the process exhaust gas;
gas analysis means for analyzing each component of the sampled process exhaust gas;
comparison means for comparing an analysis result from the gas analysis means with a reference analysis result of the process exhaust gas generated from a process carried out under reference process conditions; and
detection means for generating and outputting a signal indicating a process error, when it is determined from the comparison result from the comparison means that the amount of at least one gas component of the process exhaust gas has changed to an amount that is outside a predetermined range set around a reference value obtained from the reference analysis result.
With the above device in accordance with the present invention, the components of process exhaust gas are analyzed to presume that there is an error in the process conditions, and if it is determined that there is an error, a signal indicating a process error is outputted. In accordance with this signal, a notification of the error occurrence is sent to the operation manager of the device, prompting the operation manager to adjust the process conditions. The process exhaust gas is a product from an actual process carried out for the process object, and therefore reflects the actual process. Accordingly, compared with a case where each-item of the process conditions prior to the process of the process object is adjusted to a target value so as to control the reaction with the process object, a more precise control-operation for the process conditions can be performed by adjusting the process conditions based on the components of the process exhaust gas reflecting the actual reaction with the process object.
In the above device in accordance with the present invention, the gas analysis means is preferably a Fourier-transform infrared spectroscope. With the Fourier-transform infrared spectroscope employed as an analysis means having a very high analysis speed, analysis results can be obtained without delay, and the process for the object to be processed can promptly reflect the analysis results. For instance, if an error is caused in the process conditions during a process carried out for process objects in a single lot, the process can be immediately stopped, and the process conditions can be adjusted to the normal state. In this manner, a continuous process on a number of process objects under the unsuitable process conditions can be prevented before too late.
The process exhaust gas monitoring device in accordance with the present invention may further include alarm means for giving an alarm in accordance with the signal outputted from the detection means.
The process exhaust gas monitoring device in accordance with the present invention may further include control means for automatically controlling the process conditions in accordance with the signal outputted from the detection means.
The process exhaust gas monitoring device in accordance with the present invention may further include memory means for storing the analysis result from the gas analysis means. In this process exhaust gas monitoring device, the comparison means compares a plurality of analysis results with the reference analysis result.
The process exhaust gas monitoring device in accordance with the present invention may further include memory means for storing a plurality of reference analysis results. In this process exhaust gas monitoring device the comparison means compares each of a plurality of analysis results with each corresponding one of the plurality of reference analysis results.
The process exhaust gas monitoring device in accordance with the present invention may further include switch means for switching process exhaust gas passages for sampling the process exhaust gas at a plurality of locations.
The process exhaust gas monitoring device in accordance with the present invention may further include control means for controlling operations of the gas analysis means and the switch means.
The process exhaust gas monitoring device in accordance with the present invention may further include comparison result memory means for storing a comparison data resulted from the comparison means. In this process exhaust gas monitoring device, the comparison means performs a comparison operation for each process by supplying a signal from outside to the control means, and the comparison result memory means stores the comparison data from each process.
The process exhaust gas monitoring device in accordance with the present invention may further include: nitrogen gas supply means for introducing nitrogen gas used in a zero calibration operation for the Fourier-transform infrared spectroscope to gas introduction means of the Fourier-transform infrared spectroscope; and zero-calibration control means for controlling the nitrogen gas supply means so that a zero calibration operation is performed at predetermined regular intervals.
The process exhaust gas monitoring device in accordance with the present invention may further include flow rate adjustment means for adjusting a flow rate of a gas flowing from the gas sampling means to the gas analysis means. This flow rate adjustment means is interposed between the gas sampling means and the gas analysis means.
The process exhaust gas monitoring device in accordance with the present invention may further include alarm means for giving an alarm when the flow rate of the gas flowing from the gas sampling means to the gas analysis means is outside a predetermined range.
In the process exhaust gas monitoring device in accordance with the present invention, a process device that generates the process exhaust gas includes a vacuum pump for exhausting the process exhaust gas. This process exhaust gas monitoring device may further include constant flow rate control means for supplying a constant flow rate of inert gas to the vacuum pump.
Another aspect of the present invention provides a semiconductor manufacturing device that includes:
a process chamber for processing a process object under predetermined process conditions;
exhaust means for exhausting process exhaust gas generated in the process chamber; and
the above described process exhaust gas monitoring device that is connected to the exhaust means and monitors the process exhaust gas sampled through the exhaust means.
With the above device in accordance with the present invention, the components of process exhaust gas are analyzed to presume that there is an error in the process conditions, and if it is determined that there is an error, a signal indicating a process error is outputted. In accordance with this signal, a notification of the error occurrence is sent to the operation manager of the device, prompting the operation manager to adjust the process conditions. The process exhaust gas is a product from an actual process carried out for the process object, and therefore reflects the actual process. Accordingly, compared with a case where each item of the process conditions prior to the process of the process object is adjusted to a target value so as to control the reaction with the process object, a more precise control operation for the process conditions can be performed by adjusting the process conditions based on the components of the process exhaust gas reflecting the actual reaction with the process object.
Yet another aspect of the present invention provides a method of monitoring process exhaust gas containing a plurality of gas components generated from a process carried out for a process object under predetermined process conditions. This method includes the steps of:
sampling the process exhaust gas;
analyzing the components of the sampled process exhaust gas;
comparing the gas analysis result with a reference analysis result of an analysis of process exhaust gas generated as a result of a process carried out under reference process conditions; and
generating and outputting a signal indicating a process error when it is determined that the amount of at least one gas component of the process exhaust gas has changed to an amount that is outside a predetermined range set around a reference value obtained from the reference analysis result.
With the above method in accordance with the present invention, the components of process exhaust gas are analyzed to presume that there is an error in the process conditions, and if it is determined that there is an error, a signal indicating a process error is outputted. In accordance with this signal, a notification of the error occurrence is sent to the operation manager of the device, prompting the operation manager to adjust the process conditions. The process exhaust gas is a product from an actual process carried out for the process object, and therefore reflects the actual process. Accordingly, compared with a case where each item of the process conditions prior to the process of the process object is adjusted to a target value so as to control the reaction with the process object, a more precise control operation for the process conditions can be performed by adjusting the process conditions based on the components of the process exhaust gas reflecting the actual reaction with the process object.
In the above process exhaust gas monitoring method, the step of analyzing the components of the process exhaust gas may be carried out by a Fourier-transform infrared spectroscope.
The above process exhaust gas monitoring method may further include the step of giving an alarm in accordance with the signal indicating a process error.
The above process exhaust gas monitoring method may further include the step of automatically adjusting process conditions in accordance with the signal indicating a process error.
Still another aspect of the present invention provides a semiconductor manufacturing device control system that includes:
a semiconductor manufacturing device that exhausts exhaust gas during an operation;
a monitoring device for sending analysis data obtained from an analysis made by a Fourier-transform infrared spectroscope on the components of the exhaust gas from the semiconductor manufacturing device, the analysis data being sent to a data communication network; and
data accumulation control means that receives the analysis data from the data communication network, determines from the analysis data whether an error exists in process conditions of the semiconductor manufacturing device, transmits a signal indicating an error with a presumed cause of the error to the monitoring device via the data communication network, and accumulates and registers the analysis data in a database.
With the above system in accordance with the present invention, the analysis data obtained from the analysis of exhaust gas components by the Fourier-transform infrared spectroscope are registered in the database of the data accumulation control means via the data communication network. More specifically, the analysis data from various semiconductor manufacturing devices in actual operation at a device manufacturer are immediately registered in the database. The analysis data are then analyzed based on the database, so that an error detecting operation for the process conditions can be performed with a high precision. The detection result is immediately sent to each corresponding semiconductor manufacturing device via the data communication network. In this manner, the operation manager of each semiconductor manufacturing device can be promptly notified of an error.
In the above semiconductor manufacturing device control system in accordance with the present invention, the data accumulation control means may transmit the signal indicating an error and accessory information related to the error to the monitoring device. In this system, the monitoring device displays the error in the process conditions and the cause of the error on a display screen in accordance with the signal indicating the error, and also displays information related to the error on the display screen in accordance with the accessory information.
With this system in accordance with the present invention, the operation manager of each semiconductor manufacturing device can also be provided with information concerning the error, and suitable measures can be immediately taken against the error or any danger accompanying the error.
Yet another aspect of the present invention provides a method of controlling a semiconductor manufacturing device. This method includes the steps of:
sending analysis data obtained from an analysis made by a Fourier-transform infrared spectroscope on components of exhaust gas exhausted from the semiconductor manufacturing device, the analysis data being sent to a data communication network;
determining from the analysis data sent from the data communication network whether an error exists in process conditions for the semiconductor manufacturing device;
transmitting a signal indicating an error and an presumed cause of the error in the process conditions to the semiconductor manufacturing device via the data communication network; and
accumulating and registering the analysis data in a database.
With the above method in accordance with the present invention, the analysis data obtained from the analysis of exhaust gas components by the Fourier-transform infrared spectroscope are registered in the database of the data accumulation control means via the data communication network. More specifically, the analysis data from various semiconductor manufacturing devices in actual operation at a device manufacturer are immediately registered in the database. The analysis data are then analyzed based on the database, so that an error detecting operation for the process conditions can be performed with a high precision. The detection result is immediately sent to each corresponding semiconductor manufacturing device via the data communication network. In this manner, the operation manager of each semiconductor manufacturing device can be promptly notified of an error.
In the above semiconductor manufacturing device control method in accordance with the present invention, the signal indicating an error may be provided with accessory information related to the error and then transmitted to the data communication network. In this method, the error in the process conditions and the cause of the error are reported to an operation manager in accordance with the signal indicating the error, and information related to the error is also reported to the operation manager in accordance with the accessory information. With this accessory information, the operation manager of each semiconductor manufacturing device can also be provided with the information concerning the error, and suitable measures can be immediately taken against the error or any danger accompanying the error.
Still another aspect of the present invention provides another method of controlling a semiconductor manufacturing device. This method includes the steps of:
sending analysis data obtained from an analysis made by a Fourier-transform infrared spectroscope on components of exhaust gas exhausted from the semiconductor manufacturing device in operation, the analysis data being sent instantly to an analysis center;
constructing a database by accumulating the analysis data from a plurality of semiconductor manufacturing devices in the analysis center; and
controlling each of the plurality of semiconductor manufacturing devices in accordance with the database.
With the above method in accordance with the present invention, semiconductor manufacturing devices in operation at a factory of a semiconductor device manufacturer can be managed at the analysis center. In the analysis center, the database is constructed by gathering and accumulating the analysis data supplied from the semiconductor manufacturing devices in operation at the semiconductor device manufacturer. Using this database, a high-precision managing operation can be performed for the semiconductor manufacturing devices.